Commit 338d182f authored Nov 08, 2017 by Francesco Ruggeri Committed by David S. Miller Nov 13, 2017

ipv6: try not to take rtnl_lock in ip6mr_sk_done



Avoid traversing the list of mr6_tables (which requires the
rtnl_lock) in ip6mr_sk_done(), when we know in advance that
a match will not be found.
This can happen when rawv6_close()/ip6mr_sk_done() is invoked
on non-mroute6 sockets.
This patch helps reduce rtnl_lock contention when destroying
a large number of net namespaces, each having a non-mroute6
raw socket.

v2: same patch, only fixed subject line and expanded comment.

Signed-off-by: Francesco Ruggeri <fruggeri@arista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 07842561

net/ipv6/ip6mr.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -1617,6 +1617,10 @@ int ip6mr_sk_done(struct sock *sk)
		struct net *net = sock_net(sk);
		struct mr6_table *mrt;

		if (sk->sk_type != SOCK_RAW \|\|
		inet_sk(sk)->inet_num != IPPROTO_ICMPV6)
		return err;

		rtnl_lock();
		ip6mr_for_each_table(mrt, net) {
		if (sk == mrt->mroute6_sk) {